For measurement of deformation of a core of the valve move the end of a core of the valve in the directions 1 and 2 (fig. 2.116).

If deformation exceeds extreme value, replace the valve and the directing valve plug.

Core of the valve and the directing valve plug

Deformation of a core of the valve

Extreme value inlet: 0,14 mm, final: 0,18 mm.

Valves

Remove a deposit from valves.

Check each valve for existence of wear, traces of a podgoraniye or deformation of a plate and a core, if necessary, replace the valve.

Fig. 2.117. Scheme of measurement of thickness "a" of a plate of the valve

Measure thickness of "a" of a plate of the valve. If the measured thickness exceeds extreme value, replace the valve (fig. 2.117).

Plate thickness of the valve (inlet and final):

– nominal rate: 1,25–1,55 mm;

– extreme value – 0,9 mm.

Check a valve core end face surface for existence of traces of pointed corrosion and wear. If pointed corrosion or wear takes place, the surface of an end face of a core of the valve can be processed, at the same time the soshlifovka of a facet is not allowed. At big wear (the facet is absent) replace the valve.

Check a radial beating of each valve on prisms by means of the indicator of the sentry like (fig. 2.118). For check of a beating slowly rotate the valve on prisms. If the beating exceeds extreme value, replace the valve.

Extreme value of a radial beating of a plate of the valve of 0,08 mm.

Width of a working facet of the valve

Receive a contact spot print on a working facet of each valve in the usual way, that is, apply an equal layer of pritirochny paste on a saddle of the valve and rotate the valve installed in the directing plug with an easy clip of its plate to a saddle. It is necessary to use the device for grinding in of valves.

The print received on a working surface of a plate of the valve has to represent a continuous ring without gaps, width of a print has to be within the specified range.

The nominal width of a working surface of "a" determined by a contact spot print on the working surface of the valve: inlet and final – 1,1–1,3 mm (fig. 2.119).

Repair of a saddle of the valve

If the saddle of the valve has no equal contact with a plate of the valve or width of a working surface of a saddle exceeds the limit of the range stated above, then the facet of a saddle has to be restored by grinding or milling with the subsequent grinding and grinding in.

For obtaining the section of a saddle of the valve shown in the figure 2.119 use mills for saddles of valves 1. Two mills have to be used: the first to receive a facet 15 °, the second – 45 °. The second mill is used to provide the required facet width.

For obtaining the section of a saddle of the valve shown in the drawing use mills for saddles of valves 1. Three mills have to be used: the 1st – to receive a facet 15 °, the 2nd – 60 ° and the 3rd – 45 °. The third mill (45 °) is used to provide the required facet width.

Width of a facet of a saddle of a saddle of the inlet b valve: 1,1–1,3 mm.

With – grinding in of valves.

You make grinding in of the valve to a saddle in two steps, at first with use of coarse-grained pritirochny paste which is applied on a working surface, then with use of fine-grained pritirochny paste, at the same time it is necessary to use the device for grinding in of valves and to adhere to a usual way of grinding in.